sherwood G21 raw water pump

Our goal is to educate you about the purpose and function of many of the marine boat parts required to keep your boat running smoothly. Whether you're a veteran seaman or a novice, one thing you all know is that a boat comes equipped with hundreds of moving parts.

Our goal is to educate you about the purpose and function of many of the marine parts required to keep your boat running smoothly. Whether you're a veteran seaman or a novice, one thing you all know is that a boat comes equipped with hundreds of moving parts.

What You Need to Know About the Sherwood G21 Raw Water Pump

The Sherwood G21 raw water pump is unique to Pleasurecraft (PCM) engines and used specifically on the 302/351 Ford engines. They were used for decades with no design changes, so there’s a lot of service replacement for it. Like other raw water pumps, it will require maintenance and service.

The wakeboard and towboat markets are full of passionate people, so these engines get used quite a bit more than the standard recreational boat taken out only on the weekends.

The G21 is a belt driven pump vs. an engine crankshaft driven pump and features a robust mechanical seal rather than a lip seal which enhances the product and provides a longer service life.

A critical adjustment to the belt-driven pump is to make sure belt tension is correct. Make sure the belt is tight enough to spin the pump but not too tight that it puts excessive load on the shaft and bearings inside the pump. The belt tension should be checked and adjusted as needed.

The G21 raw water pump is a rebuildable item. All the service parts are available so if it needs repair it can be done. If the cost of repair starts to exceed the cost of replacement, those factors need to be weighed while making a repair.

It's easy to replace on the G21 pump and can be done with basic hand tools. Loosen the belt tension, remove the pump and remove the three bolts holding the pump housing to the body. Remove the old impeller, install the new impeller and reverse the procedure.

Regular maintenance includes the impeller which we suggest you change annually. Silt or sand being drawn through the pump can cause excessive wear requiring more frequent replacement.

An impeller kit typically lasts one season and most cost less than $50. When you think about the expense related to engine damage from a cooling problem, it doesn't make sense not to change the impeller annually.

Don't be "penny wise and pound foolish." Carry a spare impeller kit on board so you don’t lose a weekend of water skiing or wakeboarding because you don’t have an impeller readily available for replacement.

Marine Parts Troubleshooters On Call

Once a boat part has failed, it's obviously too late to repair it. When possible we've provided tips on simple ways to maintain a part to cut your cash outlay. We know you'd rather be on the water having fun than on the dock calling your marine mechanic.

That said, if you need help troubleshooting a system failure, give our technical experts a call at 866-388-0390. They'd be happy to steer you in the right direction.